A high-resolution sensing system for measuring the beat length and strain of polarization-maintaining optical fiber based on ofdr system

A polarization-maintaining optical fiber and high-resolution technology, applied in the field of distributed optical fiber sensors, can solve the problems of difficult polarization state or phase performance, unstable time and space changes of the optical fiber output polarization state, and avoid optical pulse width and data sampling. Rate limitation, fast signal processing and demodulation, effects of high spatial resolution

Inactive Publication Date: 2016-04-06
UNIV OF ELECTRONICS SCI & TECH OF CHINA
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ordinary optical fibers used in distributed optical fiber sensors are susceptible to birefringence disturbances caused by external factors such as bending, pressure, torsion, electromagnetic fields, and temperature. Unstable, so it is very difficult to use the polarization state or phase performance in the fiber

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A high-resolution sensing system for measuring the beat length and strain of polarization-maintaining optical fiber based on ofdr system
  • A high-resolution sensing system for measuring the beat length and strain of polarization-maintaining optical fiber based on ofdr system
  • A high-resolution sensing system for measuring the beat length and strain of polarization-maintaining optical fiber based on ofdr system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Such as figure 1 As shown, it is a schematic diagram of a high-resolution sensing system based on the OFDR system and Michelson interferometric structure to measure the beat length and stress or strain of polarization-maintaining optical fiber. It can be adjusted according to the measurement distance and the spatial resolution. The light generated by the linearly swept narrow-linewidth light source is converted into linearly polarized light by the fiber polarizer and injected into the polarization-maintaining fiber coupler; one output end of the fiber coupler is connected to the polarization-maintaining fiber used for strain testing, and the other end is connected to A section of polarization-maintaining fiber is used as a reference arm, and a mirror is attached to the end of the reference arm.

Embodiment 2

[0030] Such as figure 2 As shown, it is a schematic diagram of a high-resolution sensing system based on the OFDR system and the MZ interferometric structure using single-ended detection to measure the beat length and stress or strain of polarization-maintaining fibers. A section of polarization-maintaining fiber connected to the first polarization-maintaining fiber coupler as a reference arm is connected to the output end of the circulator through a second polarization-maintaining fiber coupler to generate interference, and a detector is used to detect the interference signal.

Embodiment 3

[0032] image 3 Shown is a schematic diagram of the dual-way balanced detection structure. When a point on the test polarization-maintaining fiber is strained, the beat length of this position will change, and the amount of change is proportional to the strain. At the same time, the Rayleigh backscattering signal generated at this position will propagate to the polarization-maintaining fiber coupler to mix and interfere with the optical signal returned by the reference arm, and output a beat frequency signal. The frequency of the beat frequency signal reflects the stress or strain position, and the magnitude of the beat frequency is the magnitude of the optical power at that point. The beat length at this time can be obtained by detecting the cycle of a certain polarization state optical power change, and finally the corresponding stress or strain can be obtained through the mapping model of the beat length and the change signal.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a high-resolution sensing system for measuring the beat length and strain of a polarization-maintaining optical fiber based on an OFDR system, which is characterized in that it includes a linear frequency-sweeping narrow-linewidth light source, a polarizer, an interference system, a photoelectric detector, an optical Heterodyne receiver and signal processing system, the light generated by the linearly swept narrow-linewidth light source is converted into linearly polarized light by a polarizer and then injected into the interference system, the interference system is connected with the optical heterodyne receiver through a photodetector, and the signal The processing system is connected to the optical heterodyne receiver. The system is simple in structure, fully fiber-optic, and the linear sweep frequency of the laser is controllable. Through optical frequency domain detection, it not only avoids the limitation of spatial resolution in time domain detection by optical pulse width and data sampling rate, but also obtains high spatial resolution. Optical heterodyne detection also increases the sensitivity and dynamic range of the system.

Description

technical field [0001] The invention belongs to the technical field of distributed optical fiber sensors, in particular to a sensing system for measuring the beat length and stress or strain of a polarization-maintaining optical fiber by using an OFDR system. Background technique [0002] With the improvement of the transmission rate of the communication system and the development of advanced fiber optic sensor devices such as fiber optic gyroscopes and fiber optic hydrophones, in the interferometric fiber optic sensor based on optical coherent detection, the direction of the polarization state is controlled to remain unchanged, and the coherent signal-to-noise ratio is improved. , to achieve high-precision measurement of physical quantities has become very urgent. The stress measurement of optical fiber usually adopts the quarter-wave plate method, which has been widely used in the stress measurement of ordinary optical glass and crystal. However, ordinary optical fibers u...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): G01B11/16G01L1/24
Inventor 欧中华陈玉李剑锋岳慧敏刘永代志勇
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap